DelayedDiagnostic.h revision 212795 
1//===--- DelayedDiagnostic.h - Delayed declarator diagnostics ---*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This file defines the DelayedDiagnostic class, which is used to
11// record diagnostics that are being conditionally produced during
12// declarator parsing.  Certain kinds of diagnostics --- notably
13// deprecation and access control --- are suppressed based on
14// semantic properties of the parsed declaration that aren't known
15// until it is fully parsed.
16//
17// This file also defines AccessedEntity.
18//
19//===----------------------------------------------------------------------===//
20
21#ifndef LLVM_CLANG_SEMA_DELAYED_DIAGNOSTIC_H
22#define LLVM_CLANG_SEMA_DELAYED_DIAGNOSTIC_H
23
24#include "clang/AST/DeclCXX.h"
25
26namespace clang {
27namespace sema {
28
29/// A declaration being accessed, together with information about how
30/// it was accessed.
31class AccessedEntity {
32public:
33  /// A member declaration found through lookup.  The target is the
34  /// member.
35  enum MemberNonce { Member };
36
37  /// A hierarchy (base-to-derived or derived-to-base) conversion.
38  /// The target is the base class.
39  enum BaseNonce { Base };
40
41  bool isMemberAccess() const { return IsMember; }
42
43  AccessedEntity(ASTContext &Context,
44                 MemberNonce _,
45                 CXXRecordDecl *NamingClass,
46                 DeclAccessPair FoundDecl,
47                 QualType BaseObjectType)
48    : Access(FoundDecl.getAccess()), IsMember(true),
49      Target(FoundDecl.getDecl()), NamingClass(NamingClass),
50      BaseObjectType(BaseObjectType), Diag(0, Context.getDiagAllocator()) {
51  }
52
53  AccessedEntity(ASTContext &Context,
54                 BaseNonce _,
55                 CXXRecordDecl *BaseClass,
56                 CXXRecordDecl *DerivedClass,
57                 AccessSpecifier Access)
58    : Access(Access), IsMember(false),
59      Target(BaseClass),
60      NamingClass(DerivedClass),
61      Diag(0, Context.getDiagAllocator()) {
62  }
63
64  bool isQuiet() const { return Diag.getDiagID() == 0; }
65
66  AccessSpecifier getAccess() const { return AccessSpecifier(Access); }
67
68  // These apply to member decls...
69  NamedDecl *getTargetDecl() const { return Target; }
70  CXXRecordDecl *getNamingClass() const { return NamingClass; }
71
72  // ...and these apply to hierarchy conversions.
73  CXXRecordDecl *getBaseClass() const {
74    assert(!IsMember); return cast<CXXRecordDecl>(Target);
75  }
76  CXXRecordDecl *getDerivedClass() const { return NamingClass; }
77
78  /// Retrieves the base object type, important when accessing
79  /// an instance member.
80  QualType getBaseObjectType() const { return BaseObjectType; }
81
82  /// Sets a diagnostic to be performed.  The diagnostic is given
83  /// four (additional) arguments:
84  ///   %0 - 0 if the entity was private, 1 if protected
85  ///   %1 - the DeclarationName of the entity
86  ///   %2 - the TypeDecl type of the naming class
87  ///   %3 - the TypeDecl type of the declaring class
88  void setDiag(const PartialDiagnostic &PDiag) {
89    assert(isQuiet() && "partial diagnostic already defined");
90    Diag = PDiag;
91  }
92  PartialDiagnostic &setDiag(unsigned DiagID) {
93    assert(isQuiet() && "partial diagnostic already defined");
94    assert(DiagID && "creating null diagnostic");
95    Diag.Reset(DiagID);
96    return Diag;
97  }
98  const PartialDiagnostic &getDiag() const {
99    return Diag;
100  }
101
102private:
103  unsigned Access : 2;
104  bool IsMember;
105  NamedDecl *Target;
106  CXXRecordDecl *NamingClass;
107  QualType BaseObjectType;
108  PartialDiagnostic Diag;
109};
110
111/// A diagnostic message which has been conditionally emitted pending
112/// the complete parsing of the current declaration.
113class DelayedDiagnostic {
114public:
115  enum DDKind { Deprecation, Access };
116
117  unsigned char Kind; // actually a DDKind
118  bool Triggered;
119
120  SourceLocation Loc;
121
122  union {
123    /// Deprecation.
124    struct { NamedDecl *Decl; } DeprecationData;
125
126    /// Access control.
127    char AccessData[sizeof(AccessedEntity)];
128  };
129
130  void destroy() {
131    switch (Kind) {
132    case Access: getAccessData().~AccessedEntity(); break;
133    case Deprecation: break;
134    }
135  }
136
137  static DelayedDiagnostic makeDeprecation(SourceLocation Loc,
138                                           NamedDecl *D) {
139    DelayedDiagnostic DD;
140    DD.Kind = Deprecation;
141    DD.Triggered = false;
142    DD.Loc = Loc;
143    DD.DeprecationData.Decl = D;
144    return DD;
145  }
146
147  static DelayedDiagnostic makeAccess(SourceLocation Loc,
148                                      const AccessedEntity &Entity) {
149    DelayedDiagnostic DD;
150    DD.Kind = Access;
151    DD.Triggered = false;
152    DD.Loc = Loc;
153    new (&DD.getAccessData()) AccessedEntity(Entity);
154    return DD;
155  }
156
157  AccessedEntity &getAccessData() {
158    return *reinterpret_cast<AccessedEntity*>(AccessData);
159  }
160  const AccessedEntity &getAccessData() const {
161    return *reinterpret_cast<const AccessedEntity*>(AccessData);
162  }
163};
164
165}
166}
167
168#endif
169